1. Field of the Invention
The present invention relates to a carburetor with a starting fuel supply mechanism. More particularly, it relates to a carburetor with a starting fuel supply mechanism which interlocks with the closing operation of a choke valve to open a starting fuel supply path, thereby supplying a starting fuel in addition to a usually supplied fuel at the start of an engine.
2. Description of Related Art
In a carburetor provided with a choke mechanism used for a general-purpose engine or the like, to adjust the air-fuel ratio of an air-fuel mixture to a start air-fuel ratio at the cold start of the engine, the engine is usually started while the totally closed state or arbitrary open degree of a choke valve is secured. In this case, when the flow rate of a fuel discharged through a main nozzle during cranking does not satisfy an engine demand flow rate, a start defect or inability to start is caused, and hence an extra time is something required for complete explosion.
To solve these problems, Japanese Patent Application Laid-Open No. 2002-339804 suggests a carburetor with a starting fuel supply mechanism comprising a starting fuel supply path disposed as a route other than a main fuel passage, to connect a float chamber to a suction passage. An opening/closing valve is disposed in the starting fuel supply path, and a link rod is interposed so as to connect the opening/closing valve to a choke lever, thereby opening the opening/closing valve of the starting fuel supply path with the closing operation of the choke lever.
In this way, the starting fuel supply mechanism is disposed which can prepare a starting fuel to be supplied by interlocking with the opening of the choke valve and which supplies the starting fuel through the starting fuel supply path as a bypass of the main fuel passage, whereby it is possible to avoid a situation in which the supplied fuel runs short at the cold start of the engine.
However, in the starting fuel supply mechanism suggested in the above document, the opening/closing valve of the starting fuel supply path formed in the carburetor is opened and closed on the side of the tip of the link rod connected to the choke lever disposed outside the carburetor. The constitution of the mechanism is complicated, and additionally the number of processing processes for manufacturing the carburetor and the number of components are increased. Therefore, this technology is not easily employed broadly in the carburetor for the general-purpose engine where the simplicity of the constitution and the decrease of cost are demanded.